Hydraulic fuel injector



y 1941. DIFAGUE- ,241, I

"HYDRAULIC FUEL INJECTOR Filed April 20. 1939 fjyzze INVENTOR ATTORNEYS 1 Patented May" '13; 1941 UNITED STATE s PATENT OFFICE HYDRAULIC FUEL mmo'ron John 1). Fague, Philadelphia, Pa. Application April co, 1939, serial No. 269,031

3 Claims.

My invention relates to fuel injectors for internal combustion engines. An important object of my invention is the provision of a fuel injector for an internal combustion engine that will thoroughly atomize and preheat the fuel before-combustion. V

Another object of my-invention is the provision of a fuel injector for an internal combustion engine that will substantially increase the efliciency of the engine, and .thatwill effect a more thorough burning of the fuel.

Yet another object of my invention is the provision of a fuel injector for an internal combustion engine that may be easily attached to any of the standard makes of engines.

Still another object of'my invention is th provision of a fuel injector for'an internal combustion engine that is efiicient in operation, jsimple in construction and inexpensive to manufacg Other objects and advantages of my invention will be apparent duringythecourse of the following description. I

',In the drawing, forming a part of this specification, and in which like numerals are employed to designate like parts-throughoutthe same,

Figure 1 is a vertical sectional view of'a device embodying my invention, and showing the same associatedwith an internal combustion engine,

' Figure 2 is a transverse sectional viewtaken on the line 2-2 of Figure 1, and

Figure 3 is a transverse sectional view taken on the line 33 of Figure 1.

In the accompanying drawing, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 10 designates the engine block of an internal combustion'engine having cylinder walls ll positioned therein and pistons I 2 reciprocally mounted withr in said cylinder'walls. The piston 12 is provided with the conventional piston rings 13 to permitthe same to have a close frictional engagement with the inner peripheral wall of the cylinder. 1 f I My device embodies a cylinder head it fitted to the block III in vertical abutting relation with the cylinder walls I l and having a vertically ursposed'housing l5 integrally formed therewith and disposed centrally above each of the pistons 13. It is to vbe understood that while the fuel injector is here illustrated as being associated with but oneof the pistons' that each piston .01 the motor is provided with asimilar device -incorporated into the cylinder head directly thereabove, and that while the description .will be re- 7 opening 26 at the top of thepressure cylinder I1 end of the housing l5 and in alignment'with the longitudinal center of the piston l2. The housing I5 is substantially elliptical in cross section and a bore 18 is formed therein and spaced laterally from the bore H by a transverse wall It. The bore I1 comprises a pressure cylinder and ,the lower end 20 thereof constitutes a high pres sure precombustion chamber which is indirect communication with the cylinder It and the top' of the piston l2. The chamber 20 is formed at v substantially its point of communication with .the cylinder II with an annular shoulder 2l and a substantially cup-shaped opening 22 of slightly smaller diameter than the cylinder H which opens directly onto the center of piston l2.- The bore it comprises an injector cylinder the lower portion of which terminates in a. substantially conical seat 23 which includes a laterally extending passage 24 communicating therewith and with the side wall of the pressure cylinder II a substantial distance above the shoulder 2|. The' I transverse closure wall It is provided with an opening 25 which afiords communication between the bores I1 and 18 adjacent their top. The cap screw 21 is threadedly received in an and may be removed. when it is found desirable to gain access to the said cylinder.

The built-up piston 29 is slidably mounted- -within the cylinder l1 and is formed with a plurality of piston rings 30 interposed between the sections to assure a close frictional engagement thereof with the peripheral face of the cylinder. The bottom face" of the piston 29 comprises a plate 3| formed with an upwardly extending shank 32 the end of which is threaded to receive the pal-nuts 33. The nuts 33 may be rotated longitudinally along the shank 32 to properly tension the laminated sections of the pistons and to regulate the cohesive attraction of Y the piston with the cylinder walls. The'expane sion spring 34 is interposed between the top of the piston and the'cap screw 21, and the lowerend 35 thereof receives the upwardly extending-.7

end of the shank 32 and theupper end 38 thereof receives the downwardly extending shank 28 of the cap screw 21. The spring 34 functions to normally position the piston 23'within the pre- A- built-up piston 38 is slidably mounted within the cylinder l8 and-is formed with a plurality of laminated sections 48 having piston rings 4| interposed therebetween to assure a close frictional engagement ,thereof with the inner face of the cylinder wall. The sections 48 are similarly provided with a bottom plate 42 of substantially con- "ical formation to permit the same to properly seat within the conical recess 23 of thecylinder and having an upwardly extending shank 43 the upper end of which is threaded to receive palnuts 44. The retractile spring 45 is interposed between the top of the piston 38 and a packing gland 45 which is threadedly received within the opening 31 of the housing l5. The lower portion of the spring 45 is formed with a plate-like ele- .ment 41 having a central opening adapted to receive the shank 43 and to be held in interlocking engagement between the top of the piston 48 and the lower pal-nut 44. The upper end of the spring 45 is formed with substantially plate-like structure 48 having an outwardly extending annular flange 48 adapted to be receiv within the lower portion of the opening 31 d in abutting relation with the shoulder 38. The packing gland 45 is threaded into the opening 31 and abuts the upper surface of the plate-like element 48 to hold the same securely wedged inder, controls'the inflow of the said fluid and therein. The packing gland is formed with central longitudinal bore 58 and upwardly extending shank 5| which receives the packing nut 52 to securely hold the inner end of the feed line 53 of the hydraulic fluid tank (not shown). The feed line 53 is in direct communication with the bore 58 and the spring. actuated check valve 54 is positioned in the lower portion of the bore 58 Ito-permit hydraulic fluid from within the fluid tank to enter within the cylinders I1 and I8. The retractile spring 45 functions to normally hold the piston 48 retracted within the cylinder l8 and withthe plate 42 positioned a substantial distance above its seat 23.

The laterally extending bore 55 communicates with the side wall of the cylinder |8 in a substantially constricted opening 55 at a point slightly below the normal position of. the lower end of the piston 48. A mixing valve 51 is positioned within the bore 55 and securely held therein by means of the stud bolts 58. The mixing valve 51 is formed with a longitudinally extending bore 58 which communicates with the outlet port 55, and an air inlet tube 58 is integrally connected to the valve and in communication with the outer end of the bore 58. The sleeve 5| is integrally formed with the valve 51' andpositioned within the passage 58 in annular spaced relation with the wall thereof. The sleeve 5| terminates adjacent the port 55 and in communication therewith. The fuel feed inlet pipe 52 late the mixing ratio of the fuel from the fuel line 52 with the air from the air inlet pipe 58.

The head I4 is formed with an annular internal recess'55 which encircles but does not communicate with the lower portion of the pressure cylinder l1 and the injector cylinder |'8,'and the said recess may be fllled with water, or the like, to impart a cooling effect to the cylinders.

The operation of my device is as follows:

A cylinder head constructed in accordance with the present invention may be attached to a fourcycle or a two-cycle engine with equally emca-' cious results. A hydraulic liquid is forced into the cylinders I1 and I8 above their respective pistons 28 and 48, and this hydraulic fluid'may be used to lubricate the pistons and to assure the operation thereof in an efficient and eflicacious manner. The spring actuated valve 54, positioned at the point of communication of the inlet pipe from .the hydraulic fluid tank with the cylpermits a quantity to flow into the cylinders necessary to maintain the same in a fllled condition. As illustrated in Figure 1, the valve 54 seats butwardly of the packing gland 45 in a manner to prevent the fluid from backing into the fluid inlet pipe 53 upon actuation of the pistons 28 and 48.

Assume that the cylinder head I4 is attached to the engine block of a two-cycle engine and that the power piston |2 has completed a power stroke and has uncovered the exhaust port to permit the escape of the gases and vapors within the upper portion of the cylinder The exhaust pressure in the cylinder will now be only slightly above the atmospheric pressure depending upon the pressure of the fluid resistance through exhaust valves, piping, muiliers, etc. The reduced pressure in the cylinder will permit the. expansion spring 34 to force the piston 28 into the precombustion chamber 28 and seated on the shoulder 2| to close the fuel inlet passage 24. As the piston 28 moves downwardly in the chamber |1 under the resilient action of the expansion spring 34 there will be a displacement-of the hydraulic fluid within the cylinders and the injector piston 48 will be permitted to move upwardly simultaneously therewith under the resilient action of the retractile spring 45 a sufllcient distance to uncover the fuel inlet port 55. When the needle valve 53 has been properly regulated. the requisite mixture of fuel and air will be impinged through the port 58 and into. the lower portion of the injector cylinder l8. Due to the constricted proportions of the outlet port 55 a thorough mixing of the air and fuel will be assured as it is forced under pressure therethrough. At this time the piston 28 is seated on the shoulder 2| to prevent the escape of the fuel within communicates with the interior passage of the sleeve 5 at a point diametrically opposed to the air inlet passage 58, and aneedle valve 53 extends through the packing nut 54 and packing gland 55 to terminate at the outlet end of the sleeve 5|. The needle valve 53 may be governoractuated or hand-actuated at the, discretion of the user and is adapted to be actuated longitudinally of the mixing valve to substantially reguthe'injector cylinder l8. When the power piston |2 begins the compression stroke it will close the exhaust port and cause the air inlet port to be uncovered, so that a charge of heated air will will be injected through the said inlet port, pushing out the remaining burned gases, and leaving a fresh charge in the cylinder As the power piston moves upwardly in the cylinder II it will exert a pressure on the bottom face of the piston 28 through the substantially large opening 22 sufficient to force the piston upwardly within the pressure cylinder I1 and against the action of the expansion spring 34. The upward actuation of the piston 28 will uncover the fuel passage -24 and cause a displacement of the hydraulic fluid thereabove to be eifected. The displacement of the fluid will cause a force to be cylinder l8 will be forced through the fuel passage and into the precombustion chamber 20 -of the cylinder H where it will be mixed withthe fresh charge of heated air in thepower cylinder II. The actuation of the pistons 29 and 40 will not be effected to inject the fuel from the cylinder II into the precombustion chamber 20 until the on the compression stroke, and as the fuel is forced through the'constrictedpassage 24 it will be thoroughly agitated to cause final combustion in the chamber 20 and to drive the power piston downwardly in the cylinder II on its power stroke. The combustion force created in the power cylinder hold the pressure piston 29 in the elevated position and the added impetus j imparted thereto by the final combustion will be transmitted through the 'hydraulic fluid to the upper face of the injector piston 40. The said force imparted to the injector piston by the combustion of the fuel in the chamber 20 will insure a tight seated condition thereof with the seat 23 to force all of the fuel therein through the passage 24 andinto the combustion chamber 20. As illustrated in Figure 1, it will be noted that the area of the pressure piston is substantially greater than that of the injector piston sothat the force acting on the pressure piston from the I .power cylinder is greater at all times than that acting on the injector piston. A the power piston I2 completes the power stroke, the exhaust port will be uncovered to'permit the es'cape of gases and the cycle of operation will then be repeated as hereinbefore described.

The operation of the device hereinbefore described, when used in association with a fourcycle engine, would be substantially the same. The pressure, and injector pistons in the head I It will be maintained in the combustion position, illustrated in Figure 1, while the power piston fuel from the injector cylinder to the precombustion chamber.

It is to be understood that the form of the invention, herewith shown and described, is to .15 power piston l2 approaches the top dead center be taken as a preferred example. of the same,

and that various changes in the size, shape and v arrangement of parts may be resorted to without departing from the spirit of my invention.

or the scope of the'appended claims.

Having thus described my invention, I claim: 1. In an internal combustion engine including cylinders and power pistons reciprocally mounted therein; the combination of a cylinder head covering the cylinders of the said engine and having a pair of spaced vertical bores positioned-above each of the said cylinders, one of said-bores constituting a-pressure cylinder, the lower portion of which comprises a precombustion chamber which has a substantially unconstricted communication with the related cyl-v inders, the other of the said bores constituting an injector cylinder which freely. communicates with the said pressure cylinder adjacent its top and having a constricted discharge passage communicating with. the pressure cylinder ad-' jacent its bottom; a pressure .piston mounted for reciprocation within said pressure cylinder;

an expansion spring interposed between the pressure piston and the top of the said cylinder to hold the said piston normally positioned in the precombustion chamber of the said cylinder is making the power and exhaust stroke. When the power cylinder is making the suction and compression strokes, the pistons 29 and 40 will be forced to the injecting position under the tion and that the fuel supply may be regulated and determined in the same manner as for a two-cycle engine. By placing the fuel inlet port it in direct communication with the injector cylinder l8, the formation of air pockets between the mixing valve and the injector will be substantially eliminated, and by causing the suction created within the lower portion of the cylinder ll upon the upstroke of the piston 40 to draw the fuel charge into the cylinder, the use of mechanically operated valves have been eliminated and the force created by the power piston on its compression stroke will be positively hydraulically transmitted to the injector piston to assure the complete expulsion of the and to. close the said discharge passage; an injector piston mounted to reciprocate within said injector cylinder; a tension spring connected to the top of the said injector bore and to the said injector piston to hold the said piston normally retracted from the bottom of the cylinder and above the said, discharge passage; and a fuel mixing valve communicating with the said injector cylinder below the tion of the said injector piston.

2. An injector comprising a casing having spaced parallel bores of unequal diameters, one end of the larger bore opening exteriorly of the casing, one end of the smaller bore having an essentially unrestricted communication with the larger bore at the end thereof remote from the outlet end. and an essentially constricted communication with the larger bore adjacent its outlet end; a fuel supply means communicating with the smaller bore adjacent the last-mentioned end; pistons slidable in the bores, the larger piston being normally positioned to close the last-mentioned end of the smaller bore, and the smaller piston being normally positioned to permit" a charge of fuel to be introduced therein; and means to supply a hydraulic fluid above the pistons, whereby movement of the larger piston away from its outlet end and in a direction to open the last-mentioned end of the smaller bore will effect displacement of the hydraulic fluid to move the smaller piston into obturating relation with the fuel supply and to force the fuel charge therein into the larger bore.

3. An injector comprising a casing haying spaced parallel bores constituting pressure and injector cylinders, respectively, said pressure cylinder opening exteriorly of the casing at one end and with the other end thereof in unrestricted communication with the injector cylinder, said injector cylinder being formed at one normal retracted posiend of the injector cylinder will effect a displacement of the hydraulic fluid .to drive the injector valve against its seat to impinge the charge of fuel into the pressure cylinder, and wherein combustion oi the fuel in the pressure cylinder will cause the pressure valve to act upongthe injector valve through the medium of the hydraulic fluid to drive the said injector valve into pressed engagement with its seat to assure 10 a complete expulsion to the said fuel charge.

JQHN D. FAGUE. 

